Unsalted butter for preparing the baking dish
For the filling:
48 ounces frozen unsweetened pitted sweet cherries, fully thawed
1 cup sugar
1/4 cup cornstarch
2 tablespoons Grand Marnier, or other orange-flavored liqueur
For the crust:
8 ounces semisweet chocolate, coarsely chopped
1 stick unsalted butter
4 extra-large eggs
1 extra-large egg yolk
1/2 cup sugar
1 teaspoon vanilla extract
1/4 cup flour
2 pints vanilla ice cream, for serving
If you are going to bake the cobbler immediately after preparing it, preheat the oven to 375 degrees with the rack in the center position. Have ready a buttered 9-by-13-inch glass baking dish.
To make the filling, drain the cherries over a large mixing bowl.
Reserve 1/2 cup of the cherry juice; discard the rest. Place the cherries in the bowl. In another, smaller bowl, stir together the reserved 1/2 cup cherry juice, the cup of sugar, cornstarch and Grand Marnier. Pour the sugar mixture over the cherries and mix well. Transfer the cherry mixture to the baking dish. (The cherries can be prepared up to 1 day ahead and refrigerated. Remove the baking dish from the refrigerator and preheat the oven when you start to prepare the crust.)
To make the crust, melt the chocolate with the butter in a medium metal bowl set over, but not touching, a pan of simmering water, or in a microwave-safe bowl in a microwave oven. When the mixture is smooth, remove the bowl from over the water to cool.
Place the eggs and yolk, sugar and vanilla in a large mixing bowl. With an electric mixer on high speed, beat the mixture for 5 to 7 minutes, until it is very pale and has tripled in volume. Reduce the mixer speed to medium, sprinkle the flour over the egg mixture, and beat until the flour is incorporated. Use a large rubber spatula to thoroughly fold in the melted chocolate mixture. (The crust batter can be made and refrigerated in the bowl for up to 8 hours; bring to room temperature, then pour it over the cherries and bake as directed.)
Stir the cherry mixture in the baking dish, then spread the chocolate batter over it. Bake for 30 to 35 minutes, until the surface of the crust, appears dry, a skewer inserted into the crust has moist crumbs attached, and the fruit is bubbling. The cobbler is wonderful served warm; allow
it to cool for 15 to 20 minutes, then serve with vanilla ice cream.